Double-acting pump



June 14, 1949. J. "r. LEONARD DOUBLE ACTING PUMP s Shets-Sheat 1 Original Filed Feb. 15, 1946 T m m p a a Z m W 1| w M m J M M H a (L 00 6 5 WW M 1 w y. d 1 3F. t i1 Y W m. mw E l U r a in T w z 1 mm \w Q 3A W 7 M 4 h i l lwwal M l M i ITYZ June 14, 1949. J. T. LEONARD Re. 23,122

DOUBLE ACTING PUMP Original Filed Feb. 15, 1946 1 3 Shets-Sheet 2 [Iliori in-a1 Filed Feb. 15. 1946 3 Sheets-Sheet 3 0 3 a m i i. WW 6 a n 6 5 w w M 3 aw m w M 6 2 2 5 HT 4 7 Wm I 4 2 6 IHMH Reissued June 14, 1949 DOUBLE-ACTING PUMP John T. Leonard, Evanston, Ill.

Original No. 2,440,411, dated April 27, 1948, Serial No. 647,769, filed February 15, 1946. Application for reissue filed November 2, 1948, Serial 11 Claims. 1

This invention relates to a double-acting pump designed for use in a lubricant distributing system.

One object of the invention is to provide a simple and durable pump'structure adapted for economical manufacture.

Another object of the invention is to provide a lubricant pumping unit with valve mechanism incorporated therein by which the unit is adapted for use in a reversible system arranged to lubricate a plurality of bearings connected in the system.

It is also an object of the invention to provide a lubricant pumping unit for periodically supplying lubricant to a group of bearings, and to provide at the pumping device a pressure responsive indicator to show when the lubricant has reached all the bearings of the group.

Other objects and advantages of the invention will appear from the following description, taken in connection with the drawings, in which:

Fig. 1 is a vertical sectional view of a double acting lubricant pump embodying this invention and taken substantially as indicated at line l-| in Fig. 2;

Fig. 2 is a horizontal sectional View of the pump taken substantially as indicated at line 2-2 in Fig. 1;

Fig. 3 is a transverse vertical section taken substantially as indicated at line 3-3 in Fig. 2; and

Fig. 4 is a detail sectional view taken substantially as indicated at line 44 in Fig. 2.

The pump which is the subject matter of this invention is intended particularly for use in a lubricating system of the type in which a plurality of metering valves or control valves for individual bearings of the system are connect-ed between a pair of feed lines which are supplied alternatively with lubricant fed into the system at intervals from the pump; the metering valves are so arranged that the system is reversible, the lubricant being fed to the valves from one supply line until all valves of the system have been actuated to supply lubricant to bearings connected with them, and the flow being then, or at a subsequent operating period, shifted so as to cause the valves to be operated by lubricant from the other line either for lubricating the same bearings or for feeding lubricant to a second group of bearings connected to the same valves. Distributing valves of this character are described in Patent #2,260,497 to John B. Whitted. dated October 28, 1941, being shown in Figures 20 to 24, inclusive, therein.

As, shown in the drawings, the pump structure is mounted in a hollow base [0 having an upstanding flange l2 in which there is secured a tank or reservoir l4 for the lubricant to be distributed by the pump. The tank I4 is provided with the usual follower piston 16 having a piston rod [8 which extends slidably through the top wall 20 of the tank to serve as an indication of the quantity of lubricant remaining therein. The base l0 has projecting from it a fitting 22 adapted for connection with a hose or pipe through which lubricant may be supplied for filling the tank l4, and inside the base [0 the fitting 22 feeds through a cylindrical screen 24 which is secured between an upstanding lug 26 and the threaded annular portion 28 of the fitting 22 which is screwed into the side Wall of the base 10.

A sump or supply chamber 30 is formed in the base III by partitions cast integrally therewith, this chamber being in open communication with the lower end of the tank l4. A casting 32 secured in the bottom wall of the chamber 30 and forming a portion of said bottom wall, is provided with a pair of vertical bores 34, 34 which are counterbored and threaded at their upper ends to receive the cylinders 36, 36 of the pump. Each of said cylinders is provided with a piston 38 reciprocable therein, and said pistons are arranged to be actuated alternately by cam arms 40, 40 extending from opposite sides of a hub 42 which is fixed to an operating shaft 44. The base IB includes integral bearings 46 and 48 for said shaft 44, and outside the base [0 the shaft is bent at right angles to provide a handle portion 50. Preferably the shaft emerges from the base Ill through a stufiing box 52 and it is retained in its bearings by means of a set screw 54 having its inner end portion engaged in a groove 56 in the shaft. The inner end of the shaft is flattened on one side at 58 and the hub 42 is similarly formed for interengagement therewith. The upper end portion of each of the pistons 38 is formed with a notch 60 which embraces one of the cam arms 40, thus providing positive drive connections by which the rocking of the shaft 44 serves to reciprocate the pistons 38 in opposite directions.

Each of the cylinders 36 has inlet ports 62 which communicate with the interior of the sump or chamber 30 so that as each piston 38 reaches the upper limit of its movement, it uncovers the inlet ports 62 and admits a charge of lubricant to the cylinder. At its lower end each cylinder is provided with a ball check valve 64 normally seated by a spring 66 and adapted to be forced open by the downward stroke of the piston 38 to admit lubricant from the cylinder to a passage 68 formed in the casting 32.

The passage E8 intersects a bore 10 in the casting 32 in which there is fitted a slide valve 12 having a reduced portion 14 which provides an annular space I6 communicating at, all times with the portions of the passage 68 extending from both cylinders 36, 35. Thus the lubricant is first expelled from one cylinder and then from the other into passage 68. When the valv meme ber 12 is positioned as shown in Figure 1, the space 78 communicates with an outlet port 18 having threaded connection with a feed pipe A of the lubricating system. Such feed pipe may he, understood as leading to the metering valveor the system, said valves being operated by the lubricant pressure applied through the feed pipe A. A return pipe B leads back from the metering valves and is connected into the port 80 in the casting 32. With the valve (2' positioned as shown in Figure 1, the port 8i! registers with a groove 82 in the valve member from which the ports 84 connect with a passage 86 extending axially in said valve member 12 and opening through one end of said member into a chamber 88 at the end of the bore 10. A port 98 in the wall of the chamber 38 is connected by a pipe 92 with a sump or chamber. 30, as seen in Figures 2 and 3. In order that the pressure of the lubricant fedthrough the outlet port 78 and pipe A shall be effective to actuate the metering valves, any opposing pressure upon thev valve must be relieved; such relief is afiforded by way of the return pipe B which opens freely into the chamber 30. It should also be understood that all parts of the valves are kept normally filled with lubricant and that when the valves are actuated some. of this lubricant is displaced and is fed back through the pipe B the system in this manner, the operating handle 50 is rocked back and forth repeatedly to actuate both. pistons 38: so that lubricant is fed alternately from the cylinders, 36 into, the passage 68 and to the, outlet [8.

I om n me s, ach. d t ib ti o metering valve of such a system servestwo: bearings; accordingly when ones series of bearings has been lubricated as. just described the flow of r ca t rev r ed. through h s st m t serve the. remaining; bearings. In other cases. each metering valve serves; only one bearing but is arranged so that lubricant'is fed to the bearing When pre e is ap l d o; the. ys em i m direction, and; is. again fedto the hearing when pressure is: appl d: n he pposite i cti nv If the pump unit oft is inv nt o s: e p oy d n a system of the first type, the valve 12- will be shifted immediately after the, lubricant has fully traversed the system in one direction, and the pump will then be operated to, feed lubricant in the opposite direction, that is, through the. port 80 and pipe B to the va ves, wi hpipeA servin as: the return passage. to the sump 39, If the system is of the second; type described, the valye I2 will be, shifted only, at 11116 intervals t. which re-. lubrication is required by, the, bearings of the system. v

. The manually perable leve 9. e ga ed, with the valvemember- [2 may; be, actuated tov shift it to-the position shown, in Figure; 2,, in which the space 16 c cts. t e. passa e w th, the; port 80 while a groove 96 int-he valve member registers w th the port 1.8-, Wit the v ue. l s motion the lubricant discharged from the pump cylinders 35, 36 flows out into the system through the port 86 and returns by way of the port I8. The groove 96 is connected by ports 93 with the axial passage 85 in the valve member 72, thus providing for discharge of the return flow into the chamber 88 at the end of the bore 10 and thence into the sump 30 by way of the pipe 92. A spring pressed ball detent I00 is engageable with a groove I02 when the valve 12 is shifted to the first position above described, and engages in the groove H14 in the valve member when the latter is shifted to its second described position, as shown in Figure 2.

It may be understood that in systems of the type for which this pumping unit is intended the lubricant which is fed under pressure through the pipe A to. the metering valves is not discharged directly therefrom to the bearings to be lubricated but is utilized to shift certain movable parts of the valves and is then stored in said valves until they are next actuated by pressure applied through the pipe 3 Accordingly, when all the valves of the system have been operated and filled with lubricant furnished through the pipe A, there is no place for additional lubricant to go; therefore, continued operation of the pumping pistons 38, 38 will tend to build up the pressure rapidly in the pipe line A and passage 68.

A short continuation of the passage 68, denoted at 69 in Figures 3 and 4, is connected by a tube H. with an indicator which comprises a cylinder '13 with a plunger '15 slidable therein, and a reduced portion or stem 11 on the plunger exposed at the end of the tube 'H', A spring 19 resists outward movement of the plunger but upon the application of sufficient pressure to the tube ll said spring is overcome and the plunger protrudes to the dotted line position indicated at 15a in Figure 4, The spring [9 may be made strong enough tov resist the maximum pressure which it to the chamber 3%]. Tofeedthelubricant through is considered may be necessary to feed, lubricant tov the bearings by operation of the metering valvesabout 2000. lbs. per square inch-and when this pressure is exceeded in, the pipe line A and passages 68 and 69 the indicator plunger l5 will be operated as described, When the pumping action is discontinued, the pressure in the passage 69' and tube II will subside or will be relieved immediately upon reversal. of the valve ii! and, hus e mit e indi tor plunger E5 to return to its normal position.

B fo th pu piis aga act a ed th va ve.- 12 will be shifted by means of its. hand lever 94 so that the e t pe i n f he; pump w l e d lubricant under pressure through the port 8!! and pipe line B. This, will have the efiect of shifting. movable; parts in they metering valves. to expel the lubricant stored therein, from the pre vious operation, thus feeding, such. lubricant in suitably measured, quantities to individual bear! ings and filling the metering; valves, with charges of additional lubricant to, be sim-ilarly discharged atthe next operation.

It will be seen, that the mechanical construction of the pumping; unit to which this inventionis directed is: relatively simplev and requires av mini-i mum amount of machining for finishing princl pal parts The, hollow cast base ID; will require only the finishing of the bearings 46 and 48 for the rock shaft 44- and; the tapping. of a hole. for; the; threaded inlet; fitting 28, except that the underside of the; sump 3 0 will be drilled andteppsd a ndicat d at 16. iriE sure 2 to re eive screw X-WhiQ he. a tock: 32 s ached, Practically all the precision W0 3 required is concentrated in the block 32 which includes the bore 10 for thevalve 12, the communicating ports 18 and B and a suitable opening for the spring detent I 00. This block also includes the openings 34 in which the cylinders 36 are secured and the aligned threaded openings for the hollow caps I08, H18 in which the check valve springs 66 are seated. The passage 68, 69 is drilled to intersect the bores 34 and is threaded at its outer end to receive a vent fitting Hi3 having a needle valve with a knurled head i [2 by which the valve may be opened occasionally to relieve any air pressure which may be trapped in the pump.

While there is shown and described herein certain structure embodying the invention and illustrative thereof, it is to be understood that the invention is not limited thereto or thereby, but embraces all changes and modifications in its various features which may come within the scope of the appended claims.

I claim:

1. In a pump of the ciass described, a hollow base casting which includes an upwardly open sump, a block fitted into and forming a portion of the bottom wall of said sump, said block having a vertical bore threaded at its upper end, a pump cylinder having its lower end portion fitted into said bore and having a threaded portion engaging said upper end portion of the bore, said block having a horizontal bore and a transverse bore connecting said vertical and horizontal bores, said block having also a pair of outlet ports which intersect said horizontal bore, a slide valve member movable in said horizontal bore to connec't the outlet bores alternatively with said transverse bore, and a piston reciprocable in said cylinder.

2. In a pump of the class described, a hollow base casting which includes an upwardly open sump, a block fitted into and forming a portion of the bottom wall of said sump, said block having a vertical bore threaded at its upper end, a pump cylinder having its lower end portion fitted into said bore and having a threaded portion engaging said upper end portion of the bore, said block having a horizontal bore and a transverse bore connecting said vertical and horizontal bores, said block having also a pair of outlet ports which intersect said horizontal bore, a slide valve member movable in said horizontal bore to connect the outlet bores alternatively with said transverse bore, said valve member having a longitudinal passage with lateral ports positioned to connect said passage to said outlet ports alternatively, the longitudinal passage of the valve member opening into the horizontal bore, conduit means connecting a portion of said horizontal bore with the sump, and a piston reciprocable in said cylinder.

3. In a pump of the class described, a hollow base casting which includes an upwardly open sump, a block fitted into and. forming a portion of the bottom wall of said sump, said block having a pair of vertical bores threaded at their upper ends, a pair of pump cylinders having their lower end portions fitted into said bores respectively and each having a threaded portion engaging the upper end portion of the bore, said block having a horizontal bore and a transverse bore connecting both said vertical bores with the horizontal bore, said block having also a pair of outlet ports which intersect said horizontal bore, a slide valve member movable in said horizontal bore to connect the outlet ports alternatively with said transverse bore and a pair of pistons reciprocable respectively in said cylinders, to-

gether with a rock shaft journalled in said hollow base and earns thereon engageable with said pistons for actuating them.

4. In a pump of the class described, a hollow base casting which includes an upwardly open sump, a block fitted into and forming a portion of the bottom wall of said sump, said block having a vertical bore threaded at its upper end, a pump cylinder having its lower end portion fitted into said bore and having a threaded portion engaging said upper end portion of the bore, said block having a horizontal bore and a transverse bore connecting said vertical and horizontal bores, said block having also a pair of outlet ports which intersect said horizontal bore, a slide valve member movable in said horizontal bore to connect the outlet bores alternatively with said transverse bore, a piston reciprocable in said cylinder, together with a pressure indicator comprising a cylinder mounted in a wall of said hollow base, a plunger having a portion adapted to be protruded from one end of the cylinder, spring means opposing such protrusion of the plunger, and conduit means through which the pressure developed in said transverse bore is applied to the other end of said plunger.

5. In a pump of the class described, a hollow base casting which includes an upwardly open sump, a block fitted into and forming a portion of the bottom wall of said sump, said block having a pair of vertical bores, a pair of pump cylinders having their lower end portions fitted respectively into said bores, said block having a horizontal bore disposed midway between the lower end portions of said vertical bores and a transverse bore which intersects said horizontal bore and both vertical bores with a portion of said transverse bore extending beyond one of the vertical bores, said block having also a pair of outlet ports intersecting the horizontal bore at longitudinally spaced portions thereof, a slide valve movable in said horizontal bore to connect said outlet ports alternatively with said transverse bore and the cylinder, a pair of pistons reciprocable in said cylinders, a check valve for each cylinder at its lower end, said cylinders having lateral inlet ports exposed in the sump, and a pressure indicator connected to said extension of the transverse bore for response to the pressure developed therein.

6. In a pump of the class described, a hollow base casting which includes an upwardly open sump, a block fitted into and forming a portion of the bottom wall of said sump, said block having a vertical bore threaded at its upper end, a pump cylinder having its lower end portion fitted into said bore and having a threaded portion engaging said upper end portion of the bore, said block having a horizontal bore and a transverse bore connecting said vertical and horizontal bores, said block having also a pair of outlet ports which intersect said horizontal bore, a slide valve member movable in said horizontal bore to connect the outlet bores alternatively with said transverse bore, a piston reciprocable in said cylinder, said cylinder extending upwardly into the sump and having a lateral inlet port exposed therein and uncovered by the piston at the upper limit of its reciprocation.

7. In a pump of the class described, a hollow base casting which includes an upwardly open sump, a block fitted into and forming a portion of the bottom wall of said sump, said block having a vertical bore threaded at its upper end, a pump cylinder having its lower end portion fitted into said bore and having a threaded por- 7 'tion engaging said upper end portion of the :bore, said block having a horizontal bore and a transverse bore connecting said vertical and horizontal bores, said block having also a pair of outlet ports which intersect said horizontal bore, a slide valve member movable in said horizontal bore to connect the outlet bores alternatively with said transverse bore, a piston reciprocable in said cylinder, together with a ball check valve seating upwardly against the lower end of said cylinder, the lower end of said bore in the block being threaded and a hollow threaded cap secured therein with a spring for the check valve pocke'ted in said cap.

8. In a pump of the class described, a hollow base casting which includes an upwardly open sump, a block fitted into and forming a. portion of the bottom wall of said sump, said block having a pair of vertical bores, a pair of pump cylinders having their lower end portions fitted respectively into said bores, said block having a horizontal bore disposed midway between the lower end portions of said vertical bores and a transverse here which intersects said horizontal bore and both vertical bores with a portion of said transverse bore extending beyond one of the vertical bores, said block having also a pair of outlet ports intersecting the horizontal bore at longitudinally spaced portions thereof, a slide valve movable in said horizontal bore to connect said outlet ports alternatively with said transverse bore and the cylinders, a pair of pistons reciprocable in said cylinders, and a manually operable air vent valve in said extension of the transverse bore and accessible outside the hollow base. 9. In a pump of the class described, a, hollow base which includes an upwardly open sump, the bottom portion of said base being formed to provide the bottom wall of said sump, said bottom portion having a pair of vertical cylinder bores horizontal bore, a slide "valve member movable in said horizontal bore to connect the outlet alternatively with saidtransverse bore, :zand'a :pair .of pistons .reciprocable respectively in said vertical cylinder bores, a rock shaft journaledin-said hollow base, and means on the rockishaitengageable with said pistons for actuating them.

10. In a pump :of the class described, a. base structure including an upwardly open sump and a bottom portion, a vertical cylinder bore in said bottom portion, said bottom portion having a horizontal bore and a transverse :bore connecting said vertical cylinder bore and said horizontal bore, said bottom portion :having also a pair of outlet ports which intersect said horizontal 'bore, a slide valve member movable in said horizon-tail here to connect the outlet boresalternatively with said transverse bore, and a piston reciproca-ble .in said vertical cylinder bore.

11. In a pump of the class described, an up wardly open sump including a bottom portion, a pair of vertical cylinder bores formed in said bottom portion, a horizontal bore and a transverse bore connecting said vertical cylinder bores with the horizontal bore, said bottom portion having also a pair of outlet ports which intersect said horizontal bore, a slide valve member .movable in said horizontal bore to connect the outlet ports alternatively with said transverse bore, a pair of pistons reciprocable respectively in .said cylinder bores, a rock shaft .journalled in the wall of said sump, and arms on the rock shaft engaging said pistons .for actuating them.

JOHN T. LEONARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,168,937 Hillis .Aug. 8,, I939 2,170,327 'Hi'llis Aug. .22, 1939 

